zaurus.inc: add xinput-calibrator to XSERVER

Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
linux-yocto*: explicitly declare KCONFIG_MODE

The default for fragment-based recipes is '--alldefconfig'
but using defconfig it is necessary to specify it.
(An hidden bug in the kernel tools has masked that until now...)

Signed-off-by: Andrea Adami <andrea.adami@gmail.com>